CLOUDY SWELLING 329 



CLOUDY SWELLING i 



The characteristic appearance of organs the seat of cloudy 

 swelling, which is frequently likened to a " scalded " appearance, 

 suggests that the change consists in a coagulation of the cell 

 proteids, which idea is supported by the similarity of the micro- 

 scopic changes observed in the cells and the earliest microscopic 

 changes observed in cells after heating gently to about their 

 maximum thermal point. On the other hand, the granules in 

 cloudy swelling are generally described as being soluble in 

 dilute acetic acid and dilute KOH, which indicates that they 

 are not the result of ordinary heat coagulation. If we bear in 

 mind, however, that cloudy swelling probably does not repre- 

 sent one single change, it may be possible to arrive at some 

 understanding of the chemical changes that occur in the process. 

 Albrecht 2 considers, with good reason, that we may have a 

 granular appearance of cells which is simply an exaggeration 

 of the normal granular structure, and, although it may be 

 observed in tissues moderately affected by toxins, or in starva- 

 tion, or in transitory anemia, the change is still to be looked 

 upon as little more than physiological in reponse to stimuli and 

 overwork. Such a " cloudy swelling " may also occur in cells 

 in the beginning of autolysis, or simply under the influence of 

 salt solution. If the injury is greater, however, as in profound 

 sepsis, or extreme local anemia, the granules become coarser, 

 less soluble in acetic acid and KOH, and droplets resembling 

 " myelin " make their appearance. If the injury is still more 

 severe, true coagulation of the granules occurs, and they become 

 insoluble, the fatty droplets become more prominent, and the cell 

 reaches a condition that may with propriety be termed necrosis 

 or fatty degeneration, or both. There is no very sharp line 

 separating necrosis and cloudy swelling, especially if we con- 

 sider only the changes in the cytoplasm. In the earliest stages 

 the granules are perhaps due, in some cases, to simple aggre- 

 gation of the colloids, without the development of a true coagu- 

 lation, and so the granules are still soluble. Possibly bacterial 

 toxins may also cause soluble precipitates, but this does not 

 appear to have been established. Halliburton has shown that 

 temperatures that may be reached in high fevers can cause tur- 

 bidity in solutions of cell proteids, and hence heat precipitation 

 may be partly responsible for the turbidity of cells in cloudy 

 swelling, but it is doubtful if the granules thus formed would 

 be soluble in acetic acid. 



1 Review of general features by Landsteiner, Ziegler's Beitr., 1903 (33), 237. 



2 Verb. Deut. Path. Gesell., 1903 (6), 63. 



